Co-curing agents for epoxy resins
First Claim
1. A unitary, storable, heat-curable epoxy resin system, which comprises a polyepoxide and a curing amount of a combination comprising (1) an epoxy curing agent and (2) a co-curing agent prepared by reacting (a) a polyepoxide with (b) a N-substituted piperazine or a N-substituted homopiperazine, wherein said piperazine is substituted with an alkyl, substituted alkyl, cycloalkyl, aryl or aralkyl group of up to 12 carbon atoms and said homopiperazine is substituted with an alkyl group of up to 3 carbon atoms, said co-curing agent having a ratio of epoxy groups to secondary amino groups of at least 0.8:
- 1.
0 Assignments
0 Petitions
Accused Products
Abstract
A N-substituted piperazine or N-substituted homopiperazine adduct with a polyepoxide is used as a co-curing agent in epoxy resin systems containing a polyepoxide and a known curing agent such as dicyandiamide, a carboxylic acid anhydride, or a dihydrazide. The preferred adducts have a ratio of epoxy groups to secondary amino groups of between 1.2:1 and 3:1. The preferred polyepoxides are polyglycidyl ethers of 4,4'"'"'-isopropylidenediphenol (bisphenol A). Suitable adducts are prepared from N-methyl-, N-(2-hydroxyethyl)-, N-octyl-, N-phenyl- and N-benzyl piperazine and N-methyl homopiperazine.
-
Citations
22 Claims
- 1. A unitary, storable, heat-curable epoxy resin system, which comprises a polyepoxide and a curing amount of a combination comprising (1) an epoxy curing agent and (2) a co-curing agent prepared by reacting (a) a polyepoxide with (b) a N-substituted piperazine or a N-substituted homopiperazine, wherein said piperazine is substituted with an alkyl, substituted alkyl, cycloalkyl, aryl or aralkyl group of up to 12 carbon atoms and said homopiperazine is substituted with an alkyl group of up to 3 carbon atoms, said co-curing agent having a ratio of epoxy groups to secondary amino groups of at least 0.8:
-
11. A process for converting a polyepoxide into an insoluble, infusible product, which comprises heating said polyepoxide at an elevated temperature with a curing amount of a combination comprising (1) an epoxy curing agent and (2) a co-curing agent prepared by reacting (a) a polyepoxide with (b) a N-substituted piperazine or a N-substituted hompiperazine, wherein said piperazine is substituted with an alkyl, substituted alkyl, cycloalkyl, aryl or aralkyl group of up to 12 carbon atoms and said homopiperazine is substituted with an alkyl group of up to 3 carbon atoms and said co-curing agent has a ratio of epoxy groups to secondary amino groups of at least 0.8:
- 1, said heating taking place at a temperature above 50°
C. for a time sufficient to complete the cure. - View Dependent Claims (12, 13, 14, 15, 16, 17)
- 1, said heating taking place at a temperature above 50°
- 18. A process for making a thermoset article of manufacture using a heat-curable epoxy resin adhesive comprising a polyepoxide, an epoxy curing agent, and a co-curing agent prepared by reacting (a) a polyepoxide with (b) a N-substituted piperazine or a N-substituted homopiperazine, wherein said piperazine is substituted with an alkyl, substituted alkyl, cycloalkyl, aryl or aralkyl group of up to 12 carbon atoms and said homopiperazine is substituted with an alkyl group of up to 3 carbon atoms, said co-curing agent having a ratio of epoxy groups to secondary amino groups of at least 0.8:
-
20. A composition of matter, useful as a co-curing agent for polyepoxides, which comprises the reaction product of a glycidyl polyether of 4,4'"'"'-isopropylidenediphenol having an epoxide equivalent of from 175 to 600 with a N-substituted piperazine or a N-substituted homopiperazine, wherein said piperazine is substituted with an alkyl, substituted alkyl, cycloalkyl, aryl, or aralkyl group of up to 12 carbon atoms and said homopiperazine is substituted with an alkyl group of up to 3 carbon atoms, wherein said reaction product has a mole ratio of epoxy groups to secondary amino groups of between 0.8:
- 1 and 4;
1. - View Dependent Claims (21, 22)
- 1 and 4;
Specification